microRNA is a newly discovered class of endogenous, small interfering RNA. MicroRNA binds to messenger RNA and translationally represses protein levels. While over 300 microRNAs have been discovered in humans alone, their biological function, targets, expression levels and role in disease remain largely unknown. A role between microRNA expression and carcinogenesis has been proposed. There is a lack of sensitive, high-throughput methodologies to monitor the expression of microRNAs. microRNA are challenging molecules to quantify because the microRNA precursors consists as a stable hairpin and the mature microRNA is only 22 nucleotides in length. We propose to evaluate sensitive and specific real-time PCR assays to quantify the expression of the mature and microRNA precursors. The microRNA expression will be analyzed in a number of important biological conditions relating to human cancer. The microRNA expression will be determined in specific sections of cancer and normal tissue isolated by laser-capture microdissection. The expression of mature and precursor microRNAs will be compared to using real-time PCR and a cDNA micro array. microRNA expression will be studied in clinical samples of human pancreatic cancer. The unparallel sensitivity and specificity of real-time PCR as applied to this new and exciting class of regulatory RNAs should propel the field into new directions not only in cancer but in other areas of human health.